The so-called Blanchard lathe [actually, it’s a shaper since the cutter is a rotating wheel] works much like a modern key-cutting machine with a stock blank [a rough gunstock form] in place of the key blank. An iron master form, in the shape of the musket stock, slowly rotates allowing a guide wheel to roll over it and to direct, in turn, the cutting wheel as it makes identical movements on the rotating wooden stock blank.

https://www.nps.gov/spar/learn/historyculture/thomas-blanchard-and-his-lathe.htm